feat: add profile language preferences and refine toast, dropdown and history UI

src/app/mod.rs

@@ -11,7 +11,7 @@ mod pages;
 
 use axum::{
     Json, Router,
-    extract::{DefaultBodyLimit, Request},
+    extract::{DefaultBodyLimit, Path, Request},
     http::{HeaderMap, HeaderValue, Method, StatusCode, header},
     middleware::{self, Next},
     response::{IntoResponse, Response},
@@ -79,6 +79,8 @@ pub fn router(
         .route("/w/{workspace_slug}", get(workspace))
         .route("/w/{workspace_slug}/n/{note_slug}", get(note))
         .route("/health", get(health))
+        .route("/lang", get(language_catalog))
+        .route("/lang/{code}", get(language_bundle))
         .route("/robots.txt", get(robots_txt))
         .route("/favicon.ico", get(favicon))
         .route("/favicon.svg", get(favicon_svg))
@@ -240,6 +242,36 @@ pub fn router(
         .with_state(state)
 }
 
+
+async fn language_catalog() -> Response {
+    let mut response = Json(crate::i18n::metadata()).into_response();
+    response.headers_mut().insert(
+        header::CACHE_CONTROL,
+        HeaderValue::from_static("public, max-age=300"),
+    );
+    response
+}
+
+async fn language_bundle(Path(code): Path<String>) -> Response {
+    let Some(source) = crate::i18n::source(&code) else {
+        return (
+            StatusCode::NOT_FOUND,
+            Json(serde_json::json!({ "error": "Language not found" })),
+        )
+            .into_response();
+    };
+    let mut response = source.into_response();
+    response.headers_mut().insert(
+        header::CONTENT_TYPE,
+        HeaderValue::from_static("application/json; charset=utf-8"),
+    );
+    response.headers_mut().insert(
+        header::CACHE_CONTROL,
+        HeaderValue::from_static("public, max-age=86400"),
+    );
+    response
+}
+
 async fn require_csrf_token(request: Request, next: Next) -> Response {
     let method = request.method();
     let unsafe_method = method == Method::POST
@@ -324,7 +356,7 @@ fn is_file_path(path: &str) -> bool {
 }
 
 fn is_asset_path(path: &str) -> bool {
-    path == "/assets" || path.starts_with("/assets/")
+    path == "/assets" || path.starts_with("/assets/") || path == "/lang" || path.starts_with("/lang/")
 }
 
 fn is_icon_path(path: &str) -> bool {